An interactive essay by Kevin Simler:

If you’ve spent any time thinking about complex systems, you surely understand the importance of networks.

Networks rule our world. From the chemical reaction pathways inside a cell, to the web of relationships in an ecosystem, to the trade and political networks that shape the course of history.

…But as much as I’ve thought about networks over the years, I didn’t appreciate (until very recently) the importance of simple diffusion.

Diffusion is powerful.